Conventionally, a welding source is provided with a welding current value meter and a welding voltage value meter, and an operator adjusts a welding condition while checking the meter of the welding source. In order to achieve a quality control for welding and to check the abnormality of a welding apparatus, moreover, there has been a monitor device for detecting a welding current value, a welding voltage value and a wire feeding speed by means of each detector.
As a conventional technique, moreover, JP-A-6-238446 has been disclosed. In the disclosure, a wire feeding speed detector is provided on the wire inlet side of the feeding motor roller of a feeding device and a display unit capable of directly reading a wire feeding speed is disposed. In the invention, the feedback of the wire feeding speed is detected by means of a speed detector and is thus displayed.
As described above, the conventional meter and display unit have been practically used as an online monitor.
However, in a welding source which is connected to an arc welding robot and is thus used, particularly, the following functions have been required for confirming a welding apparatus and a welding condition:
1) Confirmation of a welding current value and a welding voltage value which are ordered from the arc welding robot;
2) Confirmation of an actual welding current value and welding voltage value;
3) Conformation of a wire feeding speed ordered from the arc welding robot; and
4) Conformation of an actual wire feeding speed.
The welding current value, the welding voltage value and the wire feeding speed which are ordered are displayed in order to confirm that a command given from the arc welding robot is normally sent and to confirm a difference between the value of the command, the actual welding current value, welding voltage value and wire feeding speed.
Moreover, the conventional arc welding robot gives a command for only the welding current value and the welding voltage value. For this reason, there has been only a method of guessing the wire feeding speed ordered from the arc welding robot based on the welding current value ordered from the arc welding robot.
The conventional welding source and monitor device do not satisfy the functions 1) to 4) at the same time. For this reason, an operator cannot decide the abnormality of the welding apparatus and that of the welding condition.